I didn't know that! But I did find this cleaning tips video from Erin's Hamsters very helpful - it explains how to do a cage clean without stressing your hamster or removing all his natural scent. It is worth watching - it really helped me have a better cage cleaning routine (and also saves on substrate - you need deep enough substrate as well).
https://www.youtube.com/watch?v=5jVnEjrXbww